This script is somewhat trivial. It finds all places where the color "Magenta" is used for Text color, Line color, or Fill color, and changes the color to "None" instead.

Why would you want to do this, you ask? I made a bunch of photo album page layouts that I saved in a scrapbook. Then I can just drag-and-drop them onto my photo album pages, to fill them with photos. But I set all their Fill colors to Magenta, so they layouts would be easy to see in the scrapbook preview. When I'm done with the album, I need to clear out the Magenta though, because the color bleeds through on the edges of the photos. Thus, this script.